Gait Planning And Stability Analysis Of Small Quadruped Robot

As a bionic mobile robot,quadruped robot has strong movement ability and environmental adaptability.It is one of the key research directions in the field of mobile robot,and shows a very broad application prospect in many fields,such as material transportation,resource detection,rescue and disaster relief and military reconnaissance.In this paper,a small electric quadruped robot is developed,which faces the operation in a narrow space and can achieve a certain degree of obstacle surmounting and lateral impact resistance.In this paper,the steering gear is used as the driver,and the control strategy of quadruped robot driven by position controller is studied.Aiming at the attitude reversal phenomenon of Trot gait,a foot end trajectory based on ZMP(Zero Moment Point)is proposed,which improves the motion stability of Trot,and is verified by simulation and experiment.Quadruped robot is a highly coupled system of mechanical system and hardware system.Reasonable mechanical and hardware system can realize the function of robot more effectively.This paper analyzes the leg configuration of quadruped robot,determines that the single leg adopts the configuration scheme of three degrees of freedom,and completes the single leg structure design.The knee joint adopts crank connecting rod mechanism to concentrate the leg mass on the hip and reduce the moment of inertia of the leg.Analyze the overall configuration scheme of the robot,determine the overall configuration scheme of full elbow,and complete the overall structure design of the robot.The hardware system adopts the hardware system scheme of Stm32f103Rct6 as the main control chip,MPU6050 as the attitude sensor,steering gear as the driver and Wi Fi control signal transmission to complete the design of the robot body.The kinematics modeling of quadruped robot is the theoretical basis of control system.In this paper,the single leg forward kinematics,inverse kinematics and Jacobian matrix of quadruped robot are calculated.The problems of foot position acquisition and foot position control are solved by forward and inverse kinematics solutions;Jacobian matrix solves the problem of foot speed control.Trot gait is a widely used gait in quadruped robot,and the fuselage will turn over in the process of movement.This paper makes a theoretical analysis on this phenomenon from two aspects of statics and joint reaction force.In order to solve this attitude reversal phenomenon,the robot foot end compound trajectory design based on ZMP robot stability criterion is completed.At the same time,the foot trajectory planning method is adopted to realize the attitude stability of the robot under interference.The virtual model of quadruped robot is established by using ADAMS dynamic simulation platform,and the simulation experiment of the foot end trajectory is carried out by means of MATLAB and Adams joint simulation.Complete the prototype production,embed the control system framework into the microcontroller,and finally carry out the prototype experiment.The experimental results show that the foot trajectory designed in this paper can inhibit the attitude reversal of Trot gait to a certain extent.